Hi Lindaewing3,
The better options or possibilities I’m aware of in the Brentood area (subject to the guidelines here) are included in the San Francisco/Oakland/Berkeley region list in post #2 here and in the Modesto area list in post #7 here.
I have done some fairly detailed research within about 40 - 50 miles of the Stockton area and the Livermore area and I’m not aware of any additional options that I would seriously consider that are closer to you although of course it’s always possible that there is a store that has some good quality/value mattresses that I’ve missed or that I’m not aware of.
Phoenix